文献类型：期刊文献

英文题名：Metabolic engineering Corynebacterium glutamicum to produce triacylglycerols

作者：Plassmeier, Jens[1];Li, Youyuan[1,2];Rueckert, Christian[1];Sinskey, Anthony J.[1,3]

机构：[1]MIT, Dept Biol, Cambridge, MA 02139 USA;[2]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[3]MIT, Engn Syst Div, Cambridge, MA 02139 USA

年份：2016

卷号：33

起止页码：86

外文期刊名：METABOLIC ENGINEERING

收录：;EI(收录号：20155101696117);WOS:【SCI-EXPANDED(收录号:WOS:000367323000009)】；

基金：Youyuan Li was supported by the China Scholarship Council (CSC), the Fundamental Research Funds for the Central Universities of China and the Open Funding Project of the State Key Laboratory of Bioreactor Engineering.

语种：英文

外文关键词：Corynebacterium glutamicum; Metabolic engineering; TAG biosynthesis; Triacylglycerol; Microbial lipids

摘要：In this study, we metabolically engineered Colynebacterium glutamicum to produce triacylglycerols (TAGs) by completing and constraining a de novo TAG biosynthesis pathway. First, the plasmid pZ8_TAG4 was constructed which allows the heterologous expression of four genes: three (atf1 and ati2, encoding the diacylglycerol acyltransferase; pgpB, encoding the phosphatidic acid phosphatase) to complete the TAG biosynthesis pathway, and one gene (tadA) for lipid body assembly. Second, we applied four metabolic strategies to increase TAGs accumulation: (i) boosting precursor supply by heterologous expression of tesA (encoding thioesterase to form free fatty acid to reduce the feedback inhibition by acyl-ACP) and fadD (encoding acyl-CoA synthetase to enhance acyl-CoA supply), (ii) reduction of TAG degradation and precursor consumption by deleting four cellular lipases (cg0109, cg0110, cg1676 and cg1320) and the diacylglycerol kinase (cg2849), (iii) enhancement of fatty acid biosynthesis by deletion of fasR (cg2737, TetR-type transcriptional regulator of genes for the fatty acid biosynthesis), and (iv) elimination of the observed by-product formation of organic acids by blocking the acetic acid (pqo) and lactic acid production (ldh) pathways. The final strain (CgTesRtcEfasEbpIpZ8_TAG4) achieved a 7.5% yield of total fatty acids (2.38 +/- 0.05 g/L intracellular fatty acids and 0.64 + 0.09 g/L extracellular fatty acids) from 4% glucose in shake flasks after process optimization. This corresponds to maximum intracellular fatty acids content of 17.8 + 0.5% of the dry cell. (C) 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.